A numerical computer model with post-stall analysis capability was established to simulate an augmented turbofan engine.The model was based on stage-by-stage compression control volumes.A technique based on steady flow and a pseudo-flow area was developed to simulate the splitter flow at fan exit.Numerical method was established using MacCormack’s explicit difference scheme and characteristic boundary treatment.Reducing nozzle throat area was used to induce post-instability operation and the sequences of events leading to surge were investigated.Afterburner-fuel cutdown transient simulation was established to investigate the elimination of surge.The typical behavior and performance of the turbofan engine during surge cycle and the process of surge elimination were obtained.